What is the value of x in the proportion below 5/7 = x/21

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

State if the two triangles are congruent. if they are, state how you know?

The total number of dental clinics total for the last 12 months was recorded